Query abt the context switch

nobody wrote on Saturday, March 04, 2006:

Hello Sir,
                   I’m an engineering student from India. I really appreciate the work u ve done . I juz went through the source code and I’m having some doubts about the the tick ISR. In ur code, the tick is saving the context of the currently executing task even before checking whether there exists a higher priority task or not.

Is’nt it better to check for higher priority tasks and then saving the context?

I’m not a geek and perhaps my interpretations might be wrong. If so , can u pls clarify my doubt regarding this???

Thanx in advance

nobody wrote on Saturday, March 04, 2006:

Please only use English spelling not abbreviations.  People for whom English is not a first language cannot understand words like "juz" so will not get the benefit from reading your post.

Checking for a context switch prior to saving the context is not easy because the code used to check for the switch will change the processor registers meaning an incorrect context would be saved.  Adding code to prevent this scenario would be counter productive and loose you most of the benefit that might have been gained.